Anti-influenza drugs and their biological targets. The relevant viral proteins (color-coded) and old and new drugs targeting them are shown (not drawn to scale). The genomic ribonucleoprotein complex is shown as tightly coiled. Influenza viral RNA synthesis occurs in the infected host nucleus using this ribonucleoprotein as a template, while translation occurs in the cytoplasm. Neuraminidase (NA) and the drug candidate, Fludase, cleave the sialic acid receptor on the cell membrane, as indicated by the cutting scissors. Nonstructural proteins (only NS1 is shown) are not packaged in mature virions. Diverse viral products activate an inflammatory response that can be quelled by the use of anti-inflammatory treatments, such as non-steroidal anti-inflammatory drugs. Potential future drug regimens, targeting influenza-relevant cellular functions, are shown at the bottom. (Influenza virion image credit: Dan Higgins and Doug Jordan, CDC Public Health Photo Library, image #11822). HA: hemagglutinin; IFN: interferon; NA: neuraminidase; NS: nonstructural protein; RNP: ribonucleoprotein.